问题 填空题

重50牛的物体在水平支持面上做匀速直线运动,所受的阻力是20牛,则它受到的水平拉力是 ______牛,若物体在水平方向上移动30米,则拉力对物体做了 ______焦的功,重力对物体做了 ______焦的功.

答案

因物体做匀速直线运动,故在水平向上受力平衡,即拉力F=f=20N;

拉力对物体做功W=FS=20N×30m=600J;

因重力竖直向下,物体位移沿水平方向,故重力不做功.

故答案为:20,600,0.

阅读理解

阅读理解。

     New Year's Eve is a time to celebrate and enter the new year with a smile on your face. This year, there're

plenty of local activities for all ages and interests, so the smiles will come easily.

     BLUE CONCERT

     Blues band the Coyotes is playing at the Dance Barn,at 8 Barn View in Sudden Valley, The show will start

at 9 p. m. and benefit the charity Bikers Fighting Cancer. Tickets cost $10 in advance and $15 at the door. Call

224-2308 for more information.

     NEW YEAR'S LAUGHS

     Ring in the New Year and laugh out the old one at the Upfront Theatre Comic improvisers will hit on all the

highlights of the year with The Last Laugh of 2008. The 9 p. m. show will cost $15 and is open to all ages. The 11 P. m. show is to 21 and older and costs $18, which includes a champagne (香槟酒) toast. Call 733-8855 for more information.

     MAZE

     For a fun activity earlier in the evening,walk the labyrinth (迷宫) at the Leopold Crystal Bellroom. Wander

through the maze, based on the French Chartres Cathedral, for free from 4 to 9 P. m. Call 752-0048 for more

information.

     COUNTRY DANCING

     At the Bellingham Eagles Hall, live local music will help get the dance started at 8 p. m. Tickets are $15 for

adults, $10 for students and free for kids 12 and younger. For more information, call 676-1554.

1. In what way do these activities have in common?

A. They're all held in the same day.

B. They're all held by the same organization.

C. They're all organized for children.

D. They're all about the dancing and music.

2. Which of the following activities may be free for Tom aged 16?

A. COUNTRY DANCING.

B. NEW YEAR'S LAUGHS.

C. MAZE.

D. BLUE CONCERT.

3. If you want to know something about the Coyotes at 8 Barn view, you'd better call _____.

A. 676-1554

B. 733-8855

C. 752-0048

D. 224-2308

4. Which of the followings will be the highlights of NEW YEAR'S LAUGHS?

A. Wander through the maze.

B. The champagne toast.

C. Its live music.

D. The Last Laugh of 2008.

5. It can be inferred from the text that _____.

A. $10 is enough to book a ticket to Blue Concert

B. you can read the text on a telephone book

C. all these activities are international ones

D. New Year's Laughs will hold shows three times

判断题